Surface disk space: a bit better, and a bit worse, than Microsoft says

The 32GB Surface has more than the 16GB free that Microsoft says.

Microsoft's Surface tablet comes in two varieties: a model with 32GB of integrated flash storage, and a model with 64GB. That flash storage is used for everything; it houses the operating system, recovery data, and a page file, and it's also where apps, music, and video (and any other user data) get placed. As a result, that 32 or 64GB doesn't translate into 32 or 64GB of usable space.

How much are you left with? ZDNet's Ed Bott spotted that Microsoft has published a "disk space FAQ" that attempts to tackle this question. Per the FAQ, the 32GB Surface units have 16GB available. 64GB units have 46GB available.

Why so much disk space in use? A confluence of factors. First there's the time-honored problem of the computerized misuse of standard SI prefixes: a 32GB Surface has about 32 billion bytes of disk space, but operating system vendors, in their infinite wisdom, decide that "giga-" does not mean 109 but rather 230.

This is a time-honored inconsistency. Elsewhere in the computing sphere, the SI prefixes are used correctly; gigabit Ethernet, for example, has a raw data rate of 109 bits per second. Hard disks have their aereal densities typically measured in units of 109 bits per square inch. This inconsistent use of terminology, hardware engineers on the one hand using SI properly, software developers on the other using powers of two to make the mathematics simpler, consistently leads to dashed expectations, as hard disks and other storage media appear to shrink when installed and formatted. Although this misuse of SI terminology is irksome, the alternative is felt by most people to be unspeakably ugly. Hereafter, we will use GB to mean 230 bytes, and spell out billions of bytes.

Using this notion of "giga-", 32 billion bytes should come to 29.8 gigabytes, and 64 billion bytes should come out to about 59.6 gigabytes. They should, but they don't. 32GB Surfaces report their disk as having a total size of 29.0GB; 64 GB units as 58.12GB. That's 31.1 billion bytes, and 62.4 billion bytes. Those totals don't even round to Microsoft's advertised 32 and 64GB figures. Perhaps some of the space is taken up by the spare area used by SSDs to extend their lives, but it's a little shady to include that space in the advertised number, since there's literally no way of using it.

Second, there's the way the space is organized. Those 29GB are split into four separate partitions. The first, at 0.3GB, and last, at 3.52GB, are described as recovery partitions. Together, they can be used to completely wipe the machine and restore it from scratch. Windows RT has no equivalent to iOS's plaintive "please plug me into iTunes for I am hosed" boot screen, which makes sense for a system billed as a standalone PC, but means that the restore image has to be stored somewhere. The second partition is a 0.2GB affair, used to store EFI boot data. It's mostly empty.

Third, there's the stuff that's preinstalled. The remainder of the disk space, weighing in at either 27 billion bytes or 58 billion bytes, for a formatted capacity of 24.9 and 54.1GB respectively, is where everything else lives. On a freshly reset Surface, the operating system, page file (two of them, in fact; pagefile.sys and swapfile.sys), and Office RT Preview total 7.86GB. You can't really do much about this. Even if you don't want Office, there's no easy way to remove it, as it doesn't appear in Add/Remove Programs.

This leaves 17GB free on the 32GB Surfaces, and 46GB on the 64GB models. That's slightly more generous than Microsoft's own number for the 32GB units.

Shrinkage

However, that number can shrink further, as soon as you start to update the device. Every Surface RT has about 500MB of Office RT patch available, to upgrade the productivity suite to the final RTM version. Windows Update stores this patch, and any others, for about ten days after a successful installation. Installing the patch requires even more space. Applying the initial barrage of patches and adding an optional component such as a different language will chew up a good gigabyte of space on patches, and can occupy 1.5GB during installation.

Making this worse still, the Windows Store for some reason retains old versions of apps. Even after an application has been successfully upgraded, its previous version will hang around. This space just goes missing; although the Windows 8/RT Settings app can give you a breakdown of app-by-app disk usage, it only accounts for the current version of the app. The old ones are ignored. As with Office, the basic built-in applications need updating on a fresh Surface system. The result? You'll lose half a gigabyte, maybe more, to these old apps.

How long the Store keeps the old versions isn't immediately clear; the system will certainly retain at least three versions, and possibly more.

As such, even the 16GB that Microsoft promises on the 32GB Surface may not be readily available to end-users. Surface does, at least, have a way of adding storage that Windows itself will never use for its own needs; it has a microSD slot that works with 64GB cards.

There are wrinkles to this support, however. Due to the sandboxing and security used in Windows RT, apps need special permission to use this removable storage. Apps that just have permission to access your music, picture, or document libraries can't use the SD card. Worse, it's not possible to add removable storage to the existing libraries; Windows requires that all library locations be indexed. As a result, it won't index removable storage, presumably on the basis that it might get removed, which would cause the index to include information about files that no longer existed.

There is a trick involving Junction Points to make Windows not realize that the SD card is an SD card, but that is hardly what one would call elegant or easy-to-use.

Is this enough? The disk space overhead of Windows RT is larger than that of iOS or Android, and essentially eliminates the possibility of Microsoft ever shipping Windows RT devices with 16GB of disk space. A 32GB Surface has a lot less usable disk space than a 32GB Android or iOS tablet, and while this can be expanded with SD, that's not as clean or convenient as one would like. If you want to load up your Surface with media, this makes the 64GB device more compelling—but you pay a hefty price premium for the privilege.

I don't understand why Microsoft didn't just develop a separate tablet OS for the Surface RT. You can only put Metro apps on it because 3rd party desktop apps are disallowed. But it comes with essentially a full copy of Windows 8 (clocking in at nearly 12GB alone).

So you've got a simplified tablet OS with the space and resources requirements of a full fledged desktop OS. Seems like it would be nicer to just have a separate "Metro OS" for the RT.

Due to the sandboxing and security used in Windows RT, apps need special permission to use this removable storage. Apps that just have permission to access your music, picture, or document libraries can't use the SD card. Worse, it's not possible to add removable storage to the existing libraries; Windows requires that all library locations be indexed. As a result, it won't index removable storage, presumably on the basis that it might get removed, which would cause the index to include information about files that no longer existed.

So the SD slot is essentially useless unless you want to manually manage files. Users don't want to manage their files, and have repeatedly shown that they are largely incapable of doing so.

Is it just me, or does someone else notice something wrong with this statement?

I see nothing wrong with that. The device has 32 GB of flash memory (or however its measured). And will come with more than 16 GB free on arrival. Being clear about it is good, I can see lots of way's they could mislead but they aren't.

As many early reviews pointed out, Surface is really device with too many compromises. Not that I would not like to get one to play with but could not justify paying the same amount as iPad4 for device with lower res screen, no apps and now basically same available storage as 16GB iPad.

If Microsoft wants to compete, it will have to lower the price by at least $100 but that would not play nice with all the OEMs that Microsoft still needs at this stage of being transformed to fruit company.

I always thought that it was the hard disk manufacturers that used the 10-power based byte measures while everyone else used the 2-power based byte measures. That was why Windows always underreported disk size: the hard disk manufacturers decided to use the 10-power based numbers to inflate the expected size of the disk. Further than that, I thought that RAM and flash memory always used the 2-power measures.

I expect there's something else going on with the disk size being under reported, such as partitioning overhead or something like that, not the old disk size unit confusion.

Somebody correct me if I'm wrong, but I think that discussion just muddied the waters.

well, i think it happens with apple and android too, but they keep it to a gig or two out of sixteen... microsoft is using more than half the advertised space on what's likely the most popular model. i wouldn't be surprised if some enterprising law firm drew up a class action.

Is it me, or should Microsoft perhaps develop a rescue partition that uses Wifi or USB flash drive to download and install a clean image (Air-esq). This could take up maybe 100MB and give a lot more space back to the user, with the advantage that the unit gets the latest version when re-iniitialized.

On the whole HDD GB SI issue, the solution must surely be for the drive manufacturers to simply all agree to start using SI numbers for HDDs. Ironically, with SSD there is likely more of a reason to use non-SI scales than with a HDD due to the scaling on flash, but it can't be hard to make a GB a GB even then, as drives need free space to map out bad areas anyway.

I always thought that it was the hard disk manufacturers that used the 10-power based byte measures while everyone else used the 2-power based byte measures. That was why Windows always underreported disk size: the hard disk manufacturers decided to use the 10-power based numbers to inflate the expected size of the disk. Further than that, I thought that RAM and flash memory always used the 2-power measures.

I expect there's something else going on with the disk size being under reported, such as partitioning overhead or something like that, not the old disk size unit confusion.

Somebody correct me if I'm wrong, but I think that discussion just muddied the waters.

Just to keep things sane I'll use GiBi for power of 2 gigabyte and GB for power 10. I don't need to get into a debate about who's right. I just need to be able to communicate clearly.

Ram is in GiBi because that is natural from how it's laid out and addressed.

Flash size is generally in GB even tho it is laid out and addressed very similarly to Ram. This helps it match HD mfgs and they use the "extra" space that a 8GiBi drive has over a 8GB drive to act as some of the spare space for all the tricks they need to do.

Windows always reports disk sizes in GiBi so I'm sure there is some loss of space due to that conversion and you are probably right about there also being some space lost to partitioning also.

As far as who's right?

I don't doubt that the HD mfgs decided to use GB instead of GiBi because they happened to get slightly larger numbers but at the same time it's confusing to have a prefix that means two different things depending on the context. Kilo, Mega, Giga and Tera should all have a single power of 10 meaning.

After you upgrade Office Preview to the final version of Office, and install all the Windows Updates, you have about 12-13 GB of useful space left. I feel like this is barely enough as a media consumption and games device.

On a side note, what happens on a Surface if your recovery partition is hosed? It has a USB port, but can it boot from it? Hopefully there is a way to do a complete repartition/reinstall from a USB stick - but then again why would they give out copies of WinRT when it only runs on the tablet anyway...

Look, the whole units issue isnt hard. 1 GB is 1 billion bytes or 1000^3 bytes. The HDD manufacturers are using GB correctly, Microsoft isnt. There actually is notation for powers of two-based prefixes: Kibi, Mebi, and Gibi denoting 1024^1, 1024^2, and 1024^3 respectively. Abbreviations are Ki, Mi and Gi. Microsoft is using ten based prefixes to denote two based ones.

Yet another thing about Windows 8 that is poorly thought out. In my opinion, if Metro would have been a completely separate OS glaring problems like MicroSD not being able to house data for the media APIs would have solutions. Instead, the Windows team was able to use its Win8 go to excuse "you can do that in the other environment" (in this case the desktop). Of course if Metro was completely separate it would never gain any market share.

Realistically, its HDD/SDD manufacturers that are wrong. GB, MB, KB, were all used for binary prior to 1998. After having been used for binary for decades, you can't really expect people to change. Software and RAM makers use GB as binary, because they aren't shady like HDD/SDD manufacturers. Using GB as decimal allows them to to use a loop hole to put a larger number on the box. Clearly, everything having to do with storage, software, OSes, currently uses binary. Why would you use it as decimal?

You might want to add some information on the behavior of outlook, Multiple user profiles, and other logging/etc payloads.

Outlook: Yep, it's outllook. I've found no way to mrestrict, as with mail clients on other mobiles simply using an exchange conenctor, how much mail is downloaded, or to force outlook to not download pictures or attachments until later. That means if you piont it at an IMAP or Exchange account, its going to download ALL your mail (by default only the last 12 months, but then it keeps everything it downloads, and all mail you search for in history beyond that, and will continually grow from there forward, it does not auto-purge old mail) that you have not deleted from the server. It won't downlod images on new mail until you tell it to, but if you already set that flag on old mail, it does redownload. My few email accounts, including a near 8 years history in one, amount to well over 5GB of mail. Once downloaded, deleting it also deletes it serversite. The only way I know to avoid this is to use POP, which 2 of my serviers do not allow. The lack of local storage management for email in RT means you'll eat through a lot of that space very fast. Also, the "download headers only" option in Office 2013 has been completely removed, so if you reset the machine or account, you can't pull in headers quick and let mail download in the background, you have to wait for potentially several GB of mail to download 1 message at a time.

Additional users: for each user, windows createds a TON of crud. On Win 7, it;s between 500MB and 2Gb per user best i can tell by the time the user simply runs a few apps, browses the web and creates a few favorites. Each user has their own internet history, and it can grow pretty fast. Windows also creates a ton of other per-user logs. I have not taken the technical dive to see how much RT is creating per user vs Win 7 or Win 8, but i assume the load is substantial vs iOS or Android which creates very, very little user data, and are limited to one user.

logging: This is inherently, full Windows. We have no idea what limits have been placed on logging in RT vs Windows, but an average windows machine can have several GB of log files pretty easily.

Oh, and don't forget about free space. Android and iOS operate just fine with only a few MB free storage. Windows, below 1GB, will start to complain, and as storage reduces, many logging services don't back off, and can fill all remaining space down to the MB. If windows hits the end of the disk, good luck... I'm sure RT is a little more forgiving, and SSD won't have the performance dropoffs due to fragmentation that spinning disk will have, but windows can still, all on it;s own, crash itself due to logging efforts and general tasks and it;s a bear to fix if it happens (and since you can;t remote boot it from external media, that's even more of a concern).

The lack of math on the 32 and 64GB systems is concerning, where did the unallocated space go, this is a marketing issue. If it really is 1GB padded for Trim/etc, that's scary as most SSDs use some 20-30% padding, not 3%, and windows will be FAR more abusive of the flash than iOS or Android nececitating more padding for drive longevity. the multiple nearly unused partitions as well is an issue, and the device recovery parrtition shoudl be able to be copied to a USB stick and booted from there instead of guaranteeing taking up some 4GB. This is just bad design.

Combine that with your profiles and apps being relegated to internal only, and that libraries can;t span or be moved to SD, that means SD is essentialyl just an in/out repository, manual copies in and out required, it;s not an extension of the device (similar to Android's limitations, but worse in many ways). Given these issues, i can in no way reccomend less than 64GB for any general user, and would cautio media afficianados, power users, or those who plan to share a device with several family memebrs to wait for an even larger base capacity or enhqancements to RT that fix these issues.

My biggest beef, for such a low power and lmiited device, it;s incapable or replacing your Pc entirely. However, it;s not a syncable extension of your PC either. An iPad and your PC behave very nicely togehter, openly sharing files and using smart playlists and dynamically configured syncing to stay in lock step, managing contacts easily, installing and managing apps through a utility, and backing uitself up. Win RT however is a complete standalone PC. It needs AV, traditional seperate backups, and the only way to move media files on and off it are either through a cloud servic (limited in storage and performance), via manually configured file shares (insecure and unknown to most users), or manually through some undisclosed 3rd party apps/tools. There's no iTunes for Win RT either so using home sharing to move parts of your libraries or playlists is a no-go, and don;t even talk about bidirection syncing of files to keep your my-documents on both machines up to date concurrently... It has all the limitations of a tablet, and all the limitations of a PC, and Office is not even complete Office, which was it;s only real selling point (several of my spreadsheets will not open in Excel RT due to scripts or advanced features not supproted on the platform).

After you upgrade Office Preview to the final version of Office, and install all the Windows Updates, you have about 12-13 GB of useful space left. I feel like this is barely enough as a media consumption and games device.

Well, since it both lacks a media player, as well as any form of convenient way of syncing media, i guess that's a lessened issue. Of course, for me, not having that to start with is a deal breaker.

Read more about it. "use" is relative given the sandbox, profile, and library limitations imosed in RT. Essentialyl, its limited to exclusively removable storage, it;s not in any way usable as an extension of your file system. Yea, you can plug in a drive thta contains lots of music or movies, but you have to COPY what you want to internal storage forst for any app to use those files... That's not good enough.

Look, the whole units issue isnt hard. 1 GB is 1 billion bytes or 1000^3 bytes. The HDD manufacturers are using GB correctly, Microsoft isnt. There actually is notation for powers of two-based prefixes: Kibi, Mebi, and Gibi denoting 1024^1, 1024^2, and 1024^3 respectively. Abbreviations are Ki, Mi and Gi. Microsoft is using ten based prefixes to denote two based ones.

Is it just me, or does someone else notice something wrong with this statement?

I see nothing wrong with that. The device has 32 GB of flash memory (or however its measured). And will come with more than 16 GB free on arrival. Being clear about it is good, I can see lots of way's they could mislead but they aren't.

Office + OS + Pagefiles + recovery Partition + EFI = ~ 12GB, this is all required components of the OS since you can't externally boot the device for recovery.

Yep. They shoudl further refine that to the average free space accounting not just post-insitial power on, but with all logging limits in use, how much MORE will the OS tale off per user as a minimum space the user has no control over.

Windows 7, for example, will chew up 100% of a 32GB partition over time. I know because I initially built my worstation that way, 32GB boot, 100GB apps drive, 1.2TB RAID for files. I installed everything on , and moved all profile folders and libraries to E:. leaving nothing but the OS, logs, and common fies, and the minimm pagefile on C: (moved the majority of pagefile to the RAID as it was the fastest volume, but you must keep some on C for logging). 8 months in, I was running out of space. Local App Data and other hidden directories in windows were several GB each using more than 10GB total space beyond the original OS imstallation, and none of it was anything i had any control over at all as a user.

Yes, i assume RT has some much tighter thresholds for logging, and wastes less data and has less overhead, but i imaging it could easily eat 2-4GB per user account (and it is a multi-user OS so that could be a concern).

I had to micromanage the space in Win 7 until i could image and replace the 32GB partition, which i did so with an 80GB partition just to be safe. Windows today is using 47GB on that partition. less than 1.5GB of it are update files. I could cull this further, but only by either running scheduled scripts to purge some things, and by moving others to other voumens, in RT neither is really an option (sandboxing rules).

Yet another thing about Windows 8 that is poorly thought out. In my opinion, if Metro would have been a completely separate OS glaring problems like MicroSD not being able to house data for the media APIs would have solutions. Instead, the Windows team was able to use its Win8 go to excuse "you can do that in the other environment" (in this case the desktop). Of course if Metro was completely separate it would never gain any market share.

GB and MB are still allowed to be binary (from above link)"Mega will mean 1 000 000, except that the base-two definition may be used"

Your own link disagrees with you. It says prior to 1998 there was no commonly accepted standard and MB was ambiguous. Thus, they felt the need to create two different standards to address each. That Microsoft has not adapted to the standard even though it has had 14 years to do so is no ones fault but their own.

Windows requires that all library locations be indexed. As a result, it won't index removable storage, presumably on the basis that it might get removed, which would cause the index to include information about files that no longer existed.

Well that's silly. Windows 7 will allow you to add a removable device to a library, index it, and fail gracefully if you open the library and the removable storage is missing/not on/etc.

My last computer (notebook) used an external disk for most of my content and user folder needs. There were definitely times that I needed to use the computer without it plugged in and when I opened the libraries in that case they simply didn't show the folders that exist on the external drive.

While Windows RT shares much of the kernel of Windows 8, it certainly is NOT, a version of Windows 8.

There are only three versions of Windows 8

Windows 8 ( Core )Windows 8 ProWindows 8 Enterprise.

Wikipedia and numerous journals have specifically referred to it as a version of Windows 8. But, in fairness to you I just noticed the Microsoft website does try to distinguish it as a new product while simultaneously saying claiming it is virtually identical.